Disease Information for Ewings sarcoma: Definition

A type of bone cancer that usually forms in the middle (shaft) of large bones; Also called Ewing"s sarcoma/primitive neuroectodermal tumor (PNET); Primary malignant bone tumors are rare; Four types make up the majority; Malignant fibrous histiocytoma (MFH) - a pleomorphic sarcoma of storiform pattern without differentiation; Osteosarcoma - similar to malignant fibrous histiocytoma with differentiation to osteoid production; Osteosarcoma - cellular cartilaginous lesion with abundant binucleate cells, myxoid areas, and pushing borders; Ewing sarcoma - small, blue-round cell neoplasm;

Genetics: Ewing sarcoma has 11/22 chromosomal translocation and EW5-FLI-1 fusion protein; Osteosarcomas shows loss of retinoblastoma and p53 suppressor genes and amplification of the genes C-myc, mdm-2, SAS, and cyclin-dependent kinase;Prevalence in USA: Rare: 5000 bone and soft tissue sarcomas per year, a practicing orthopedic surgeon may see one primary malignant tumor of bone in every five years of practice; Ewing sarcoma is less common in blacks; Age:MFH - teens and elderly; Osteogenic sarcoma - teens and early twenties; Chondrosarcoma - very young and very old; Ewing sarcoma - children, teens, and early twenties ; Male = Female; Pain with weight bearing, at rest and at night; Swelling; Bone Tenderness ; Fracture with minor trauma; Minor injury may bring attention to lesion; MFH often follows irradiation or arises in old bone infarct;

Osteosarcoma has association with loss of suppressor retinoblastoma and p53 genes; Chondrosarcoma may arise in pre-existing enchondroma or exostosis; Multiple enchondromatosis (Ollier"s disease) - chondrosarcoma; Multiple hereditary exostosis - chondrosarcoma; Previous irradiation, risk factor for MFH; Previous history of bilateral retinoblastoma - osteosarcoma; Pagets disease osteosarcoma; DDX: Solitary metastatic lesion or myeloma especially in the patient over age 40; Lymphoma at any age; Benign bone tumors and benign bone tumors that look aggressive (aneurysmal bone cyst, giant cell tumor, eosinophilic granuloma); Infection (osteomyelitis); Metabolic bone disease (osteopenia, Pagets,

hyperparathyroidism; Synovial diseases (pigmented villonodular synovitis; [Griffith clincal advisor 2005]

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